1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
26 #include <sys/sysinfo.h>
27 #include <sys/inotify.h>
33 #include "readahead-common.h"
36 int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) {
41 if (fstat(fd, st) < 0) {
42 log_warning("fstat(%s) failed: %m", fn);
46 if (!S_ISREG(st->st_mode)) {
47 log_debug("Not preloading special file %s", fn);
51 if (st->st_size <= 0 || st->st_size > file_size_max) {
52 log_debug("Not preloading file %s with size out of bounds %llu", fn, (unsigned long long) st->st_size);
59 int fs_on_ssd(const char *p) {
61 struct udev *udev = NULL;
62 struct udev_device *udev_device = NULL, *look_at = NULL;
64 const char *devtype, *rotational, *model, *id;
71 if (!(udev = udev_new()))
74 if (!(udev_device = udev_device_new_from_devnum(udev, 'b', st.st_dev)))
77 if ((devtype = udev_device_get_property_value(udev_device, "DEVTYPE")) &&
78 streq(devtype, "partition"))
79 look_at = udev_device_get_parent(udev_device);
81 look_at = udev_device;
86 /* First, try high-level property */
87 if ((id = udev_device_get_property_value(look_at, "ID_SSD"))) {
92 /* Second, try kernel attribute */
93 if ((rotational = udev_device_get_sysattr_value(look_at, "queue/rotational")))
94 if ((b = streq(rotational, "0")))
97 /* Finally, fallback to heuristics */
98 if (!(look_at = udev_device_get_parent(look_at)))
101 if ((model = udev_device_get_sysattr_value(look_at, "model")))
102 b = !!strstr(model, "SSD");
106 udev_device_unref(udev_device);
114 bool enough_ram(void) {
117 assert_se(sysinfo(&si) >= 0);
119 return si.totalram > 127 * 1024*1024; /* Enable readahead only
120 * with at least 128MB
124 int open_inotify(void) {
127 if ((fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
128 log_error("Failed to create inotify handle: %m");
132 mkdir("/dev/.systemd", 0755);
133 mkdir("/dev/.systemd/readahead", 0755);
135 if (inotify_add_watch(fd, "/dev/.systemd/readahead", IN_CREATE) < 0) {
136 log_error("Failed to watch /dev/.systemd/readahead: %m");
137 close_nointr_nofail(fd);
144 ReadaheadShared *shared_get(void) {
146 ReadaheadShared *m = NULL;
148 mkdir("/dev/.systemd", 0755);
149 mkdir("/dev/.systemd/readahead", 0755);
151 if ((fd = open("/dev/.systemd/readahead/shared", O_CREAT|O_RDWR|O_CLOEXEC, 0644)) < 0) {
152 log_error("Failed to create shared memory segment: %m");
156 if (ftruncate(fd, sizeof(ReadaheadShared)) < 0) {
157 log_error("Failed to truncate shared memory segment: %m");
161 if ((m = mmap(NULL, sizeof(ReadaheadShared), PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
162 log_error("Failed to mmap shared memory segment: %m");
169 close_nointr_nofail(fd);